Hmm, apparently I'm supposed to email you. Not sure how I'd have found this ending if no-one had mentioned it here. Invis is the key (and the incinerator fuel helps too) because the guards wander off if you are invis, except the one you are hacking on ...
But you still get kicked straight out into the endgame. Damn guys, I wanted to go back and kill every living thing in the lands (giants too) .. guess I'll have to do it before teleporting to the finish.